2段简单的JavaBean代码演示了简单内省操作以及复杂内省操作 。
1、简单内省操作
package me.test;
import java.lang.reflect.*;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
public class IntroSpectorTest
{
public static void main(String []args) throws IntrospectionException, IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
JavaBeanTest t=new JavaBeanTest() ;
t.setX(10);
PropertyDescriptor d=new PropertyDescriptor("X",JavaBeanTest.class);
setProperty(t, d);
Object val = getProperty(t, d);
System.out.println(val);
}
private static Object getProperty(JavaBeanTest t, PropertyDescriptor d)
throws IllegalAccessException, InvocationTargetException {
Method mr=d.getReadMethod() ;
Object val=mr.invoke(t);
return val;
}
private static void setProperty(JavaBeanTest t, PropertyDescriptor d)
throws IllegalAccessException, InvocationTargetException {
Method mw=d.getWriteMethod() ;
mw.invoke(t, 5) ;
}
}
class JavaBeanTest
{
private int x ;
public void setX(int x)
{
this.x=x ;
}
public int getX()
{
return this.x ;
}
}
2、复杂内省操作 BeanInfo类 Introspector类的使用
package me.test;
import java.lang.reflect.*;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
public class IntroSpectorTest
{
public static void main(String []args) throws IntrospectionException, IllegalArgumentException, IllegalAccessException, InvocationTargetException
{
JavaBeanTest t=new JavaBeanTest(10) ;
PropertyDescriptor d=new PropertyDescriptor("x",JavaBeanTest.class);
setProperty(t, d);
Object val = getProperty(t, d);
System.out.println(val);
}
private static Object getProperty(JavaBeanTest t, PropertyDescriptor d)
throws IllegalAccessException, InvocationTargetException, IntrospectionException {
BeanInfo beanInfo=Introspector.getBeanInfo(t.getClass()) ;
PropertyDescriptor pt[]=beanInfo.getPropertyDescriptors() ;
for(PropertyDescriptor tem:pt)
{
if(tem.getName().equals(d.getName()))
{
Method mr=tem.getReadMethod() ;
Object val=mr.invoke(t) ;
return val ;
}
}
return null;
}
private static void setProperty(JavaBeanTest t, PropertyDescriptor d)
throws IllegalAccessException, InvocationTargetException, IntrospectionException {
BeanInfo beanInfo=Introspector.getBeanInfo(t.getClass() ) ; //把JavaBeanTest的对象当做JavaBean看有什么信息封装在BeanInfo中
PropertyDescriptor [] pd=beanInfo.getPropertyDescriptors() ; //Get All Properties From BeanInfo Class
for(PropertyDescriptor tem:pd)
{
if(tem.getName().equals(d.getName()))
{
Method mw=tem.getWriteMethod() ;
mw.invoke(t, 50) ;
break ;
}
}
}
}
class JavaBeanTest
{
private int x ;
public JavaBeanTest(int x)
{
this.x=x ;
}
public void setX(int x)
{
this.x=x ;
}
public int getX()
{
return this.x ;
}
}
